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• 1.2 Monitoring Information The hydrologic monitoring parameters and the schedules for the hydrologic monitoring programs are presented in Section 2. The monitoring sites, parameters and schedules have evolved over time as the facility has evolved and changed. The current monitoring program was substantially modified in 2001 per Permit Revision PR-04 and further modified in TR-47 in 2004. The current monitoring program can be found in Exhibit 2.05-E7 -Hydrologic Monitoring Plan of the CDMG permit. Field parameters for groundwater are depth to water level, pH, conductivity, and temperature. Field pazameters for surface water are flow, pH, conductivity, and temperature. Equipment and methods used to measure the field pazameters include: • Depth to water level - A cable marked in increments is lowered into the groundwater monitoring well until electrical continuity is reached at the water surface. • pH - A Cole Parmer pH Testr 3 pocket-size tester is used to measure the pH of a water sample. Published specifications for the pH Testr 3 are range: pH - 1.0 to 15.0, resolution: 1.0 pH, accuracy: +\- 0.1 pH, automatic temperature compensation: 0 to 50 degrees C, calibration points 1, 2, or 3. The pH tester is calibrated prior to sampling events using the 2 point method. The expected pH is bracketed by the pH of the calibration solutions. In most cases the pH tester is calibrated to 7 and 10 which brackets all of the current monitoring results. If an expected pH is less than 7, the pH tester can be • calibrated at 4 and 7. • Conductivity - A Cole Panner pocket-size TDS Testr 3 or TDS Testr 4 is used to measure the conductivity of a water sample. Published specifications for the TDS Testr 3 are range: 0 to 1990 uS, resolution 10 uS, accuracy: +\- 2% full scale, automatic temperature compensation: 0 to 50 degrees C, calibration with standard solution. Published specifications for the TDS Testr 4 are range: 0 to 19.90 mS, resolution: 0.1 mS, accuracy: +\- 2% full scale, automatic temperature compensation: 0 to 50 degrees C, calibration with standazd solution. • Temperature - A standard mercury thermometer that measures temperature in degrees Celsius is used. • Flow -The flow is measured in one of four different ways. The first method is to utilize a known culvert size combined with the depth of flow and the velocity determined by measuring the time it takes a floating object to travel a known distance. The second method is to time flow into a bucket of known size. The third is to measure the length, width, depth, and the velocity of a stream of water or sum the flows measured in segments of a larger stream of water. The fourth way, used to find the flow of the North Fork of the Gunnison, is obtained from the nearby USGS gauging station. Historically, water samples from groundwater wells H-10 and B-6 had been taken with a bailer that has a restricted inlet. The bailer is weighted so it sinks to the bottom of the well when it is empty. The water flowed into the bailer slowly so a sample of the water from the bottom of the well was obtained. It was not possible to purge wells H-10 and B-6 because they are connected • to the flooded mine workings. Recently, H-10 and B-6 wells have been dry resulting in no samples being obtained. Because of mine development activities, during 2004, B-6 was sealed.